THE INSTALLATION OF UNDERGROUND … AND OPERATION OF UNDERGROUND BOOSTER FANS North Goonyella Coal Mine Ventilation Change Scope of Work prepared and authorised by the Ventilation

INSTALLATION AND OPERATION OF UNDERGROUND BOOSTER FANS

North Goonyella Coal Mine

THE INSTALLATION

OF UNDERGROUND

BOOSTER FANS AT

NORTH GOONYELLA COAL MINE



System requirements are;-

Maintain intake Methane GB concentration

below 0.5%;

Virgin gas content increasing with depth;

Expected development advance rates increasing

to 180 m/wk;

Require 70 m3/s at last open c/t in MG development.

Ventilation Planning indicated that the current system

would be unable to meet system requirements beyond

2400 chainage in MG4N.

Main fans operating near design capacity.

VENTILATION SYSTEM PRIOR TO BOOSTER FANS



MAIN FAN PERFORMANCE PRIOR TO BOOSTER FANS

0

1000

2000

3000

4000

5000

0 100 200 300 400 500

Airflow (m3/s)

Fan

Sta

tic P

ressu

re (

Pa)

Current Fan

Duty

MG6N

MG4N

MG9N



R

R

DD

R

R

DD

780 Pa971 Pa

Main

ga

te 4

N

R

R

Main Surface Fan

226 m3/s @ 1140 Pa

47 m3/s

49 m3/s

Borehole Fan

12 m3/s @ 4500 Pa

27 m3/s

R

7 m3/s

VENTILATION PRIOR TO BOOSTER FANS



Twin fan installation located in the main return airways at G & I

headings 25 c/t.

Each fan is powered by a single 600 kW motor located in a

purpose designed intake air chamber

Centrifugal fan

Variable speed control

Designed to service the mine to LW9N

Central bypass airway to maintain mine ventilation when the

booster fan is non operational.

BOOSTER FAN INSTALLATION




Preferred option because;-

Underground pressure differentials

Cost

Timing



R

R

DD

R

R

DD

392 Pa751 Pa

Main

ga

te 4N

R

R

Main Surface Fan

282 m3/s @ 1054 Pa

50 m3/s

54 m3/s

Borehole Fan

12 m3/s @ 4500 Pa

37 m3/s

R

6 m3/s

X

DD

DD

X

D

D

XD

Twin Boosters @ 472 rpm

220 m3/s @ 800 Pa

1154 Pa

Ventilation After Booster Fan Installation



Place fan in series with existing main fans

Apply additional air power to inbye workings

Reduced ventilation pressures outbye of the booster

Increased ventilation pressures inbye of the booster

Reduction of main fan requirements for a given inbye

performance







Ventilation Pressure

Booster fans

Motor bulkheads

Bypass doors

Methane

Motor chambers

Booster fan inlet

Carbon Monoxide

Motor chambers

Fan Speed

Motor bearing – vibration &

temperature

Fan shaft bearing – vibration &

temperature

MONITORING



Frequency Responsibility Inspection

Twice / shift ERZ Controller Motors & Substation

Shiftly ERZ Controller Booster Fans

Monthly Ventilation Officer

Ventilation Adequacy

VCD Integrity

Accelerated Oxidation

INSPECTIONS



Under normal operating conditions the mine is

ventilated by:

Twins surface fans.

Both booster fans running.

Maingate borehole forcing fan.

The central bypass doors are closed when the booster

fans are running.

NORMAL OPERATING CONDITIONS



To alter the duty of either the main surface

fans, the booster fans or the borehole fan is

classified as a Major Ventilation Change and

as such requires authorisation from the

Ventilation Officer & countersigned by the

Mine Manager.

NORMAL OPERATING CONDITIONS



Ventilation Change Scope of Work prepared and authorised by

the Ventilation Officer, countersigned by the Mine Manger. Based

on ventilation modeling of the change defining:

Target face ventilation quantities.

Main fan duty

Intermediate and final booster fan speed / duty settings

Goaf pressure balance arrangements

Ventilation pressures at strategic locations

Notice of alteration to fan settings

Notification of persons affected

Alteration of booster fan, main fan and gas monitoring alarm

settings

Change validation

Ventilation model update

CHANGING SETTINGS



Single main fan operating (must be in place before

booster fans can be started)

Status check – main fan collar pressure, gas, pressure

& condition monitoring at booster fan.

Start booster fans and increase speed to intermediate

level (speed increases automatically)

By-pass door closes with increasing pressure (relies

solely on ventilation pressure for operation)

BOOSTER FAN STARTING



Start second main fan (manual, will not start unless

booster fans are running at set intermediate speed)

Increase booster fan to authorised operating duty

(Happens automatically)

Status check – main fan collar pressure, gas, pressure

& condition monitoring at booster fan

Adjust mine regulators as required

Confirm gas and ventilation monitoring

BOOSTER FAN STARTING



Normal fan operation – twin main fans, twin booster fans,

maingate borehole fan

When one booster fan trips the second booster fan is

shutdown

By-pass door opens

One of the main surface fans trips (No2.)

The development feeder power is isolated

Status check – main fan collar pressure, gas, booster fan

installation gas, pressure & condition monitoring

Confirm reason for booster fan stoppage

Underground controller to notify Shift Supervisor and

ERZ controllers

Review regulator settings where booster fan outage to be

extended

BOOSTER FAN STOPPING



Booster fans to be shutdown periodically in a

controlled and planned manner for maintenance

purposes.

Represents a Major Ventilation Change – written

authorisation of Ventilation Officer, countersigned by

Mine Manager.

Except in the case of emergencies, requires:

24 hours notice

Formal request with scope of work to be performed during

shutdown, prepared by department seeking the shutdown.

PLANNED SHUTDOWN



FAILURE MODES

Loss of power to mine site

Loss of underground power

Loss of underground power, other than the

booster fan feed

Failure of both main fans

Failure of a single main fan

Failure of both boosters fans



FAILURE MODES

Failure of a single booster fan

Failure of maingate borehole fan

ERZ trip at inbye interface

By-pass door fails to open when booster fans

shutdown

By-pass door fails to close when booster fans powered

up

Failure of Communications



Door held closed during normal operation

Door partially open – nil pressure condition

Door open upon booster fan failure

Door restrained from opening fully to enable closure

on booster fan restart.

BYPASS DOORS



INSTALLATION

Fans delivered to mine site in June/July 2002

Work began in September 2002 with secondary support

work and site clean up.

Began Excavating booster fan sites October 2002

Completed Excavating sites December 26th 2002

Laying concrete January

Erecting fans February/March

Electrical installation occurred in parallel with other tasks



EXCAVATION

Removal of 3.0m coal caunch at I hdg went well

Thickness of concrete work underestimated

G heading fan site concrete excavated approx. 1.0m thick

Concrete had mesh and roof bolts embedded inside

Excavated using combination of the following;-

• Trencher Machine to cut 700mm deep “slots”

to make excavations easier;

• Machine mounted jack picks hired (mixed success)

• Manual jack picking (brute strength).



CONCRETE WORKS

Concrete works responsibility of fan supplier (Flackt-Woods)

Concrete 40 MPa spec with reinforcing to Australian Standards

60 m3 per fan site, 120 m3 total

Subcontractor experienced difficulties in that the Reo bar

supplied from supplier in Townsville was incorrectly manufactured

Subcontractor utilised steel purpose designed formwork – resulted

in and excellent finished product

Utilised specialist concreter to supervise the concrete works



FAN INSTALLATION

Fan installation and build up went smoothly

Flackt-Woods supervised subcontractor installing fans

Fan impellors delivered on purpose designed skids for ease

of transport

Fan supplied in parts to specified sizes for transport underground.

Utilised existing skid for transportation of fan parts where reqd

Motors heaviest item (5.5 tonnes)

Surveyed transport route prior to order to identify load restrictions



ELECTRICAL INSTALLATION

Used contractors where possible to minimise drain on mine

resources

Changed schedule to allow electrical installation to occur

in parallel with other operations

Termination of heavy power cables from fan substation to

fan motors more difficult than expected

Fan supplier clearly did not understand requirements of Qld

legislation for electrical equipment such as monitors



ELECTRICAL INSTALLATION

On site support from substation and motor suppliers was good

Off site testing of substation with actual fan motor saved time

during commissioning

Very few problems encountered during the commissioning

that were related to the booster fan electrical installation

VVVF drives proven very effective in operation

Some problems encountered with the fibre optic line installation



COMMISSIONING

Commissioning period extended due to factors not related

to the booster fan installation;-

Delayed commissioning due to poor roof on Longwall

Major repairs to Trunk belt (splicing)

Requirement to weld on the Longwall face

Waiting for window for development panel extension

Major fault #2 surface fan only 1 fan available for 2 days

Major unplanned power outage to site during commissioning



COMMISSIONING

Actual commissioning period on booster fans was 5 days

Some problems encountered;-

I hdg motor coupling moved slightly (bedding in)

One vibration sensor on I hdg fan reading normal

but plc interpreted as trip (calibration problem)

One pressure sensor had blockage in stainless steel

tubing run for pressure readings (not sensor problem)

Need to dismantle and rebuild 24 I-J stopping to allow 2 surface

fan operation (due to welding on LW)



COMMISSIONING

There were many positives to the commissioning stage;-

The electrical systems worked very well

Electrical interlocks were all physically tested – all worked

Both fans ran smoothly – temperatures & vibrations

were all well within limits and stable

Ventilation pressures and quantities were all very

close to those modelled – verifying and adding confidence

to accuracy of the ventilation model

Due to the outside problems, the commissioning was very

flexible – this was able to be done and still achieve all objectives



COMMISSIONING

Support from OEMs was good, especially with the stop/start

nature of the commissioning

Able to test single fan operation of each booster fan (important

information for future)

Able to run each booster fan up to full RPM

Proved the system including the designed interlocks and operation

Fans running and commissioning over on Friday 2nd May 3:15 pm



POST COMMISSIONING

Air quantities in mine are greatly improved;-

Longwall 52 m3/s (52 m3/s prior to booster fans);

MG4N 98 m3/s at Dogleg regulator (68 m3/s prior to booster fans)

Mains H heading 45 m3/s (27 m3/s prior to booster fans);

Mains B heading inbye 35 c/t 35 m3/s (8 m3/s prior to booster fans).

Pressures inbye booster fan increased from 700 Pa to 1300 Pa

Main fan collar pressure 1060 Pa (1140 prior to booster fans)



POST COMMISSIONING

One point of note is that a very good fan curve has been developed for

the booster fans.

Could be used for all fans.

Allows for accurate prediction of fan operation.

Excellent tool for future ventilation planning.

Developed by Geogas.

D:/Fan Curve Generation NG(Booster).xls



SUBSTATION

HIGH TENSION END

TRANSFORMER

690V CB

690V VVVF DRIVE

No1

AIR CONDITIONING

PANEL



G HEADING MOTOR CHAMBER

630 kW 690v

MOTOR

This is an NERZ zone



Differential pressure transmitters

CO and CH4 gas

monitoring

BMA

IS Terminal Box

And Emergency

Stop Local Isolator and Manual

Stop Start

Vibration

monitoring



STARTUP FLOWCHART



MAIN CITECT SCREEN (SURFACE CONTROL ROOM)



BOOSTER FAN OVERVIEW SCREEN



BOOSTER FAN DETAIL SCREEN



VVVF DRIVE DETAIL SCREEN



ENVIRONMENTAL MONITORING DETAIL SCREEN















Hand operated Enapac

For brakes

Second Brake Operated

Proximity Switch

And Speed Sensor behind

Brake Disc

Brake Disc

MOTOR SHOWING SHAFT HOLDING BRAKE ASSEMBLY



THE INSTALLATION

OF UNDERGROUND

BOOSTER FANS AT

NORTH GOONYELLA COAL MINE



R

R

DD

R

R

DD

397 Pa527 Pa

Main

gate 4N

R

R

Main Surface Fan

180 m3/s @ 646 Pa

43 m3/s

29 m3/s

Borehole Fan

12 m3/s @ 4500 Pa

20m3/s

R

4 m3/s

X

DD

DD

X

D

D

XD

Booster Fans Idle

337 Pa

BOOSTER FANS STOPPED -

Effect on Mine Ventilation

Bypass Door Schematic



MG4N 200 m3/s @ 1 kPa 290 kW

MG5N 270 m3/s @ 1.4 kPa 520 kW

MG6N 290 m3/s @ 1.8 kPa 700 kW

MG8N 300 m3/s @ 2.4 kPa 970 kW

MG9N 270 m3/s @ 1.7 kPa 640 kW

COMBINED OPERATING DUTIES



Pressure Gradient Profile - MG5N

-2500

-2000

-1500

-1000

-500

0

0 1000 2000 3000 4000 5000 6000 7000

Distance from surface (m)

Ve

nti

lati

on

Pres

su

re L

oss

(P

a)

Booster Fan

Existing Surface Fan

Booster Fan

M G5 R eturn

M G5 Intake

D rif ts & M ain Intakes



SUBSTATION VENTILATION



G Hdg MOTOR CHAMBER VENTILATION



I Hdg MOTOR CHAMBER VENTILATION

Documents

THE INSTALLATION OF UNDERGROUND … AND OPERATION OF UNDERGROUND BOOSTER FANS North Goonyella Coal Mine Ventilation Change Scope of Work prepared and authorised by the Ventilation